384 
SPAESICAYEA. 
part of the stem may be bare of apertures and longitudinally 
libbed. 
The marsupial chamber is a gonocyst. 
Type Species. 
Sparsicavea carantina, d’Orbigny, 1853-4. Senonian and 
Turonian : France. 
Aefinities. 
This genus is linked to Petalopora by the species S. wrighfi^ 
Yrbicb in j^art has the typical radial ribs of Sparsicavea^ while- 
other parts of the same stem have strong longitudinal ribs and 
the maculae in longitiuhnal series. This aiTangement occurs in 
the basal parts of the stem in S. francqana, and in zones of the 
stem of S. icrighti. 
The value of the generic separation of this group from Petalopora 
may he questioned, hut in addition to the ornamentation of the stem 
there are other characters ; the marsupial chamber is a gonocyst, 
not a gonoecium, and the stems are composed of fewer zooecia with 
thinner and not laminated walls. The difference in longitudinal 
sections may be seen by comparing PI. XII. Figs. 8 and 10 with 
Fig. 49 on p. 386. 
1. Sparsicavea carantina, d’Orhigny, 1853. 
SY^’OXTArY. 
Sparsicavea carantina, d’Orbigny, 1853-4. Bry. Cret. p. 950, pi. 775, figs. 1-3. 
,, ,, Pergens Meimiev, 1887. Bry. gar. Faxe : Ann. Soc. 
mal. Beige, vol. xxi., Mem. p. 211. 
Heteropora ,, Pergens, 1890. Eevision, p. 372. 
,, ,, Pergens, 1893. Bry. St. Pat. : Bull. Soc. beige GeoL 
vol. vi., Pr. Yb. p. 208. 
,, ,, Tine, 1893. Compl. Eep. : Eep. Brit. Assoc. 1892, p. 311. 
,, ,, Pergens, 1895. Bry. Arche de Leves : Bull. Soc. beige 
Geol. vol. viii., Pr. Yb. p. 136. 
Sparsicavea franeqana , d’Orbigny, 1853-4. Bry. Cret. p. 951, pi. 775, figs. 4-6. 
Heteropora ,, Bucaille, 1890. Bry. Cret. Seine-Inf. : Bull. Soc. Sci. 
iiat. Eouen, vol. xxv. p. 512. 
,, ,, Yine, 1893. Compl. Eep. : Eep. Brit. Assoc. 1892, p. 311. 
Entalophora madreporacea, pars, Yine, 1893. Ibid. p. 309. 
Heteropora obliqua, Yine, 1893. Ibid. p. 311. 
,, irregularis, Yine, 1893. Ibid. p. 311. 
